U.S. patent application number 10/539060 was filed with the patent office on 2007-07-05 for 4,4'-biphenol polysulfone compositions, process to prepare them, and articles made thereof.
This patent application is currently assigned to SOLVAY ADVANCED POLYMERS, LLC. Invention is credited to Mohammad Jamal El-Hibri.
Application Number | 20070155871 10/539060 |
Document ID | / |
Family ID | 32681968 |
Filed Date | 2007-07-05 |
United States Patent
Application |
20070155871 |
Kind Code |
A1 |
El-Hibri; Mohammad Jamal |
July 5, 2007 |
4,4'-Biphenol polysulfone compositions, process to prepare them,
and articles made thereof
Abstract
4,4'-Biphenol polysulfone composition comprising: as main
ingredient, at least one polysulfone comprising more than 50 mol. %
of recurring units formed by reacting 4,4'-biphenol with at least
one sulfone monomer SM.sub.1 (B.sup.o1 PSU), more than 0.01% by
weight, based on the total weight of the composition, of at least
one phosphorus-containing compound chosen from organic phosphites
and organic phosphonites, and at least one polysulfone comprising
more than 50 mol. % of recurring units formed by reacting bisphenol
A with at least one sulfone monomer SM.sub.2(B.sup.o1 A PSU).
4,4'-Biphenol polysulfone composition containing at least 60% by
weight, based on the total weight of the 4,4'-biphenol polysulfone
composition, of at least one B.sup.o1 PSU, said composition having
a melt viscosity ratio at 410.degree. C. and at a shear rate of 50
s.sup.-1 (VR.sub.40) of below 1.20. Process which is especially
well-suited to prepare the above compositions. Articles made from
the above compositions or prepared by the above process.
Inventors: |
El-Hibri; Mohammad Jamal;
(Atlanta, GA) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
SOLVAY ADVANCED POLYMERS,
LLC
4500 McGinnis Ferry Road
Alpharetta
GA
30005
|
Family ID: |
32681968 |
Appl. No.: |
10/539060 |
Filed: |
December 17, 2003 |
PCT Filed: |
December 17, 2003 |
PCT NO: |
PCT/US03/40117 |
371 Date: |
February 20, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60433771 |
Dec 17, 2002 |
|
|
|
Current U.S.
Class: |
524/115 |
Current CPC
Class: |
C08K 5/5393 20130101;
C08L 81/06 20130101; C08K 5/51 20130101; C08K 5/5393 20130101; C08L
81/06 20130101; C08L 81/00 20130101; C08L 81/06 20130101 |
Class at
Publication: |
524/115 |
International
Class: |
C08K 5/49 20060101
C08K005/49 |
Claims
1-15. (canceled)
16. A 4,4'-biphenol polysulfone composition comprising: as a main
ingredient, at least one polysulfone comprising more than 50 mol. %
of recurring units formed by reacting 4,4'-biphenol with at least
one sulfone monomer SM.sub.1 (B.sup.o1 PSU); more than 0.01% by
weight, based on the total weight of the composition, of at least
one phosphorus-containing compound selected from the group
consisting of organic phosphites and organic phosphonites; and at
least one polysulfone comprising more than 50 mol. % of recurring
units formed by reacting bisphenol A with at least one sulfone
monomer SM.sub.2 (Bo.sup.o1 A PSU).
17. The composition according to claim 16, wherein SM.sub.1
comprises a 4,4'-dihalodiphenylsulfone.
18. The composition according to claim 16, wherein the B.sup.o1 PSU
consists of recurring units formed by reacting 4,4'-biphenol with
at least one 4,4'-dihalodiphenylsulfone.
19. The composition according to claim 16, wherein SM.sub.1
comprises a 4,4'-bis(4-halophenylsulfonyl)-1,1'-biphenyl.
20. The composition according to claim 16, wherein the B.sup.o1 PSU
consists of recurring units formed by reacting 4,4'-biphenol with
at least one 4,4'-bis(4-halophenylsulfonyl)-1,1'-biphenyl.
21. The composition according to claim 16, which comprises at least
60% by weight, based on the total weight of the composition, of the
B.sup.o1 PSU.
22. The composition according to claim 16, wherein the
phosphorus-containing compound consists of one or more organic
phosphites.
23. The composition according to claim 16, wherein the
phosphorus-containing compound consists of one or more organic
phosphites and one or more organic phosphonites.
24. The composition according to claim 16, wherein the
phosphorus-containing compound consists of
tris(2,4-di-t-butyl-phenyl)phosphate.
25. The composition according to claim 16, wherein the
phosphorus-containing compound consists of
tris(2,4-di-t-butyl-phenyl)phosphate monomer and one or more
organic phosphonites.
26. The composition according to claim 16, which comprises between
0.09% and 0.40% by weight, based on the total weight of the
composition, of the phosphorus-containing compound.
27. The composition according to claim 16, which comprises from 3%
to 14% by weight, based on the total weight of the composition, of
the B.sup.o1 A PSU.
28. The composition according to claim 16, which has a melt
viscosity ratio at 410.degree. C. and at a shear rate of 50
s.sup.-1 (VR.sub.40) of below 1.20.
29. A 4,4'-biphenol polysulfone composition comprising at least 60%
by weight, based on the total weight of the 4,4'-biphenol
polysulfone composition, of at least one polysulfone comprising
more than 50 mol. % of recurring units formed by reacting
4,4'-biphenol with at least one sulfone monomer SM.sub.1 (B.sup.o1
PSU), said composition having a melt viscosity ratio at 410.degree.
C. and at a shear rate of 50 s.sup.-1 (VR.sub.40) of below
1.20.
30. The composition according to claim 29, wherein SM.sub.1
comprises a 4,4'-dihalodiphenylsulfone.
31. The composition according to claim 29, wherein the B.sup.o1 PSU
consists of recurring units formed by reacting 4,4'-biphenol with
at least one 4,4'-dihalodiphenylsulfone.
32. The composition according to claim 29, wherein SM.sub.1
comprises a 4,4'-bis(4-halophenylsulfonyl)-1,1'-biphenyl.
33. The composition according to claim 29, wherein the B.sup.o1 PSU
consists of recurring units formed by reacting 4,4'-biphenol with
at least one 4,4'-bis(4-halophenylsulfonyl)-1,1'-biphenyl.
34. An article comprising the composition according to claim
16.
35. The article according to claim 34, which is manufactured by an
injection moulding process.
36. An article comprising the composition according to claim
19.
37. An article comprising the composition according to claim
29.
38. An article comprising the composition according to claim 32.
Description
[0001] Polysulfones comprising more than 50 mol. % of recurring
units formed by reacting 4,4'-biphenol with at least one sulfone
monomer (hereafter B.sup.o1 PSU) are unique members of the sulfone
polymer family. Among the B.sup.o1 PSU, polyphenylsulfones, i.e.
polysulfones comprising more than 50 mol. % of recurring units
formed by reacting 4,4'-biphenol with at least one
4,4'-dihalodiphenylsulfone (hereafter PPSU), are of particular
interest. B.sup.o1 PSU provide compositions with mechanical
properties which are usually not found in compositions based on
other polymers in their temperature class. B.sup.o1 PSU
compositions usually need to be processed at high temperature for
good melt flow behaviour; in some fabrication configurations, melt
temperatures as high as 400-420.degree. C. are required.
[0002] The problem is that, at such high temperatures, the
viscosity of B.sup.o1 PSU itself, and consequently of any usual
B.sup.o1 PSU composition, increases very much over time, and this
viscosity rise makes it very difficult to manufacture articles of
consistently high quality based on said compositions.
[0003] In addition, when manufacturing articles from B.sup.o1 PSU
itself or from a usual B.sup.o1 PSU composition, it is generally
observed that a char layer builds on the walls of tooling that is
being used (e.g. in the die in case of an extrusion process, or in
the injection nozzle in the case of an injection moulding process);
this undesirable char layer grows rapidly over time, and results in
the generation of black specks in the articles being fabricated,
thereby downgrading their performance and aesthetics. The charring
is also responsible for the generation of scrap in the form of
black speck laden extrudate. To remove the char layer from the
system, a complete shut down and clean up of the fabrication system
is needed, which is costly from the standpoint of down time and
lost production.
[0004] Attempts have already been made to improve the melt
stability of various aromatic polysulfones compositions.
[0005] GB 1 398 133 discloses that the incorporation of 0.01 to 4%
by weight of a phosphite ester can substantially improve the melt
viscosity of some varieties of aromatic polysulfones other than
B.sup.o1 PSU.
[0006] WO 03/089520, which was filed before but published on or
after the priority date of the present application, discloses that
organic phosphorus-containing compounds like organic phosphites and
phosphonites, commonly referred to as melt stabilising agents, can
be advantageously added, together with a colorant and/or an optical
brightener, to a PPSU composition, for the purpose of reducing its
yellowness and increasing its light transmittance. Amounts of
phosphorus-containing compound far below 0.1 wt. % (based on the
total weight of the composition) proved sufficient to reach the
goal.
[0007] Some commercial PPSU grades commercialised by Solvay
Advanced Polymers, L.L.C. under the registered name RADEL.RTM. R,
like Radel.RTM. R-5600 NT, consist of virgin PPSU polymer and
traces (at most 0.01 wt. %) of organic phosphites and/or
phosphonites. Said organic phosphites and/or phosphonites are added
during the recovery process of the PPSU from the solvent in which
the PPSU is dissolved just after the polycondensation reaction), in
an amount of up to 0.20 wt. % based on the amount of PPSU; however,
more than 95% of them are either decomposed into compounds other
than organic phosphites and phosphonites, or are lost during said
recovery process.
[0008] All the prior art PPSU compositions which include an organic
phosphite and/or phosphonite compound, although exhibiting
sometimes a slightly improved melt stability with regard to usual
PPSU compositions (i.e. B.sup.o1 PSU compositions totally free of
phosphite and phosphonite), have still not sufficient melt
stability at high temperature, so all the problems and drawbacks
met with said usual B.sup.o1 PSU compositions, such as the charring
and the formation of black specks, as above detailed, still occur
in an acute way.
[0009] It is also prior art to blend PPSU with bisphenol A
polysulfone, in particular for lowering the price of the PPSU
composition, with a possible drawback on the mechanical properties
of the PPSU.
[0010] As an illustration thereof, example 3 of US 2002/0017743
discloses a blend of 50 wt. % of Radel.RTM. R-5600 NT PPSU, 25 wt.
% of Udel.RTM. P 1710 NT 15 bisphenol A polysulfone and of 25 wt. %
of EMS TR 70 amorphous polyamide (available from EMS-Chemie AG of
Switzerland). US 2002/0017743 is silent on a possible impact of
bisphenol A polysulfone on the melt stability of the PPSU. More
generally, as far as the Applicant knows, no public disclosure
deals with the possible impact that a bisphenol A polysulfone could
have on the melt stability of the PPSU.
[0011] Another illustration thereof is a proprietary blend
commercially available from Solvay Advanced Polymers, L.L.C., which
consists of 55 wt. % of PPSU and of 45 wt. % of PSU.
[0012] It is an objective of the present invention to provide a
4,4'-biphenol polysulfone composition which addresses the problems
raised by the prior art B.sup.o1 PSU compositions as above
detailed.
[0013] With this end in view, the present invention concerns a
4,4'-biphenol polysulfone composition comprising: [0014] as main
ingredient, at least one polysulfone comprising more than 50 mol. %
of recurring units formed by reacting 4,4'-biphenol with at least
one sulfone monomer SM.sub.1 (B.sup.o1 PSU), [0015] more than 0.01%
by weight, based on the total weight of the composition, of at
least one phosphorus-containing compound chosen from organic
phosphites and organic phosphonites, and [0016] at least one
polysulfone comprising more than 50 mol. % of recurring units
formed by reacting bisphenol A with at least one sulfone monomer
SM.sub.2 (B.sup.o1 A PSU).
[0017] That the B.sup.o1 PSU is the main ingredient of the
composition means that its weight fraction in the composition is
greater than the weight fraction of any other ingredient which is
present in the composition.
[0018] The B.sup.o1 PSU can consist of recurring units formed by
reacting 4,4'-biphenol (i.e. 4,4'-dihydroxybiphenyl) as sole diol
with SM.sub.1. Alternatively, the B.sup.o1 PSU can comprise less
than 50 mol. % of recurring units formed from one or more diols
other than 4,4'-biphenol, such as bisphenol A,
4,4'-dihydroxydiphenylsulfone (also known as bisphenol S),
hydroquinone and 4,4'-dihydroxydiphenylether.
[0019] The B.sup.o1 PSU comprises preferably more than 75 mol. %,
and very preferably more than 90 mol. %, of recurring units formed
by reacting 4,4'-biphenol with SM.sub.1. It is most preferred that
the B.sup.o1 PSU consists of recurring units formed by reacting
4,4'-biphenol with SM.sub.1.
[0020] SM.sub.1 can be any monomer comprising at least one
--S(.dbd.O).sub.2-- group which is able to undergo a
polycondensation reaction with 4,4'-biphenol or any other aromatic
dihydroxy compound. More than 50 mol. %, and preferably the
totality, of SM.sub.1 is chosen preferably from aromatic
dihalocompounds comprising at least one --S(.dbd.O).sub.2-- group,
very preferably from 4,4'-dihalodiphenylsulfones and
4,4'-bis[(4-halophenylsulfonyl)-1,1'-biphenyl, and still more
preferably from 4,4'-dihalodiphenylsulfones.
[0021] B.sup.o1 PSU consisting of recurring units formed by
reacting 4,4'-biphenol with at least one monomer chosen from
4,4'-dihalodiphenylsulfones, gave excellent results.
[0022] The composition according to the present invention comprises
advantageously at least 60%, preferably at least 75% and more
preferably at least 85% by weight (based on the total weight of the
composition) of the B.sup.o1 PSU.
[0023] The composition according to the present invention comprises
advantageously at most 98%, preferably at most 97% and more
preferably at most 96% by weight (based on the total weight of the
composition) of the B.sup.o1 PSU.
[0024] Still more preferred compositions are those comprising:
[0025] either, from 85% to 92% by weight (based on the total weight
of the composition) of B.sup.o1 PSU ; this embodiment (hereafter,
embodiment I), is especially well suited for providing hyper melt
viscosity-stable compositions, without any substantial drawback of
the mechanical properties; [0026] or, more than 92% and up to 96%
by weight (based on the total weight of the composition) of
B.sup.o1 PSU; this embodiment (hereafter, embodiment II), is
especially well suited for providing compositions of improved melt
stability, without any drawback of the mechanical properties.
[0027] The most preferred compositions comply with embodiment
I.
[0028] The organic phosphites can be notably organic monophosphites
or organic diphosphites.
[0029] A certain class of organic monophosphites consists of those
complying with the formula ##STR1## in which two or three of the
R.sub.10 groups taken together link respectively two or three
oxygen atoms of the phosphite group. The linking group can be
notably a methylene, a propane-1,2,3-triyl or a
propane-1,3-diyl-2-ylidene group. A member of this class is:
##STR2##
[0030] The organic monophosphites that are preferred are those
complying with formula (I) as above defined, in which the R.sub.10
are selected from hydrogen and hydrocarbyl groups, optionally
substituted by one or more halogen atoms, provided that not more
than one R.sub.10 is hydrogen. The hydrocarbyl groups can be
notably cycloalkyl, alkyl, aryl, alkylaryl or aralkyl groups.
[0031] The organic monophosphites that are very preferred are
aromatic. Still more preferred are the tris(optionally alkyl mono-
or polysubstituted aryl)phosphites. Excellent results were obtained
with tris(2,4-di-t-butyl-phenyl)phosphite: ##STR3##
[0032] This phosphite is available commercially from CBI Speciality
Chemicals, Inc. under the registered name Irgafos.RTM. 168.
[0033] Organic diphosphites can consist of compounds derived from
formula (I) taken twice, in which two times two R.sub.10 (two of
each formula (I))) taken together link two phosphite groups (one of
each formula (I)). Preferred are organic diphosphites wherein the
moiety is the pentaerythritol moiety, like distearyl
pentaerythritol diphosphite or bis(2,4-dicumyl)pentaerythrytol
diphosphite and (2,4-di-t-butylphenyl)-pentaerytiritol diphosphite
of formula ##STR4##
[0034] The organic phosphonites can be notably organic
monophosphonites or organic diphosphonites.
[0035] A certain class of organic monophosphonites consists of
those complying with formula (V) ##STR5## in which the R.sub.10
(equal or different) are hydrocarbyl groups, optionally substituted
by one or more halogen atoms. The hydrocarbyl groups can be notably
cycloalkyl, alkyl, aryl, alkylaryl or aralkyl groups.
[0036] Preferred are the organic monophosphonites in which both
R.sub.10 are selected from C.sub.2-C.sub.12 alkyl groups. The
organic monophosphonites in which each R.sub.10 is
2,4-di-t-butyl-phenyl are very preferred.
[0037] Organic diphosphonites can consist of compounds of formula
##STR6## the R.sub.10 (equal or different from each other) as above
defined.
[0038] Preferred are the organic diphosphonites in which each out
of the four R.sub.10 are selected from C.sub.2-C.sub.12 alkyl
groups. The organic diphosphonites in which each R.sub.10 is
2,4di-t-butyl-phenyl are very preferred.
[0039] Any combination of the above organic phosphites and organic
phosphonites is also suitable for the purpose of the instant
invention.
[0040] A preferred combination comprises the following four
phosphorous-containing compounds: ##STR7##
[0041] Excellent results have been obtained: [0042] on one hand,
with a phosphorus-containig combination comprising from about 16 to
about 20 wt. % of (III), from about 40 to about 46 wt. % of (VII),
from about 16 to about 20 wt. % of (VIII) and from about 12 to
about 14 wt. % of (IX); such combination is available commercially
from Clariant Corp. under the registered name Sandostab.RTM. PEPQ;
[0043] on the other hand, with a phosphoms-containing combination
comprising from about 58 to about 60 wt. % of (III), from about 20
to about 23 wt. % of (VII), from about 8 to about 10 wt. % of
(VIII) and from about 6 to about 7 wt. % of (IX); such combination
is possibly a mix of about 50 parts by weight of Sandostab.RTM.
PEPQ with about 50 parts by weight of Irgafos.RTM. 168
phosphorus-containing compounds.
[0044] Single organic phosphites or mixtures of organic phosphites
(optionally in combination with one or more organic phosphonites),
especially tris(2,4-di-t-butyl-phenyl)phosphite (taken alone or in
combination with one or more organic phosphonites), have
demonstrated superior results over single organic phosphonites or
mixtures of organic phosphonites.
[0045] The composition according to the present invention comprises
preferably above 0.05%, more preferably above 0.09% and still more
preferably above 0.12% by weight, based on the total weight of the
composition, of the phosphorus-containing compound.
[0046] The composition according to the present invention can
comprise as much as 0.80, 1.00, 1.50, 2.00, 3.00 or even 5.00 wt. %
(based on the total weight of the composition) of the
phosphorus-containing compound. It comprises preferably less than
0.60%, more preferably less than 0.40% and still more preferably
less than 0.25% by weight (based on the total weight of the
composition) of the phosphorus-containing compound.
[0047] The B.sup.o1 A PSU can consist of recurring units formed by
reacting bisphenol A (i.e. 4,4'-isopropylidenediphenol) as sole
diol with the SM.sub.2. Alternatively, the B.sup.o1 A PSU can
comprise less than 50 mol. % of recurring units formed from one ore
more diols other than bisphenol A, such as 4,4'-biphenol,
4,4'-dihydroxydiphenylsulfone (bisphenol S), hydroquinone and
4-4'-dihydroxydiphenylether.
[0048] The B.sup.o1 A PSU comprises preferably more than 75 mol. %,
and very preferably more than 90 mol. %, of recurring units formed
by reacting bisphenol A with SM.sub.2. It is most preferred that
the B.sup.o1 A PSU consists of recurring units formed by reacting
bisphenol A with SM.sub.2.
[0049] SM.sub.2 can be any monomer comprising at least one
--S(.dbd.O).sub.2-- group which is able to undergo a
polycondensation reaction with bisphenol A. More than 50 mol. %,
and preferably the totality, of SM.sub.2 is chosen preferably from
aromatic dihalocompounds comprising at least one
--S(.dbd.O).sub.2-- group, very preferably from
4,4'-dihalodiphenylsulfones and
4,4'-bis[(4-halophenylsulfonyl)-1,1'-biphenyl, and still more
preferably from 4,4'-dihalodiphenylsulfones.
[0050] B.sup.o1 A PSU consisting of recurring units formed by
reacting 4,4'-biphenol with at least one monomer chosen from
4,4'-dihalodiphenylsulfones, gave excellent results.
[0051] The melt flow of the B.sup.o1 A PSU, which is measured
according to ASTM D1238 at 343.degree. C. and under a load of 2.16
kg, is advantageously greater than 4 g/10 min, preferably greater
than 8 g/10 min and very preferably greater than 12 g/10 min.
[0052] In addition, the melt flow of the B.sup.o1 A PSU, is
advantageously lower than 60 g/10 min, preferably lower than 50
g/10 min and very preferably lower than 40 g/10 min.
[0053] Still more preferred is that the melt flow of the B.sup.o1 A
PSU ranges [0054] either, from 12 to 22 g/10 min (this is
especially the case for the compositions according to embodiment I
as above defined) [0055] or, above 22 and up to 35 g/10 min (this
is especially the case for the compositions according to embodiment
II as above defined).
[0056] It is most preferred that the melt flow of the B.sup.o1 A
PSU ranges above 22 and up to 35 g/10 min.
[0057] The composition according to the present invention comprises
advantageously at least 1%, preferably at least 2% and more
preferably at least 3% by weight, based on the total weight of the
composition, of the B.sup.o1 A PSU.
[0058] The composition according to the present invention comprises
advantageously at most 39%, preferably at most 24% and more
preferably at most 14% by weight, based on the total weight of the
composition, of the B.sup.o1 A PSU.
[0059] Still more preferred compositions are those comprising:
[0060] either, from 7% to 14% by weight (based on the total weight
of the composition) of B.sup.o1 A PSU ; this range is especially
well suited for the compositions according to embodiment I as above
defined; [0061] or, less than 7% and down to 3% by weight (based on
the total weight of the composition) of B.sup.o1 A PSU ; this range
is especially well suited for the compositions according to
embodiment II as above defined.
[0062] It is most preferred that the composition according to the
present invention comprises from 7% to 14% by weight (based on the
total weight of the composition) of B.sup.o1 A PSU.
[0063] Optionally, the composition according to the present
invention can further comprise one or more other ingredients,
notably to achieve other targeted performance or processing
attributes.
[0064] These additional ingredients can include but are not limited
to fillers, lubricants, mould releases, antistatic agents, flame
retardants, anti-fogging agents, matting agents, pigments, dyes and
optical brighteners. The composition according to the present
invention is preferably free of filler, of pigment and of matting
agent.
[0065] The composition according to the present invention comprises
advantageously less than 30 wt. %, preferably less than 10 wt. %
and still more preferably less than 5 wt. % (based on the total
weight of the composition) of said additional ingredients; it is
most preferred that the composition according to the present
invention be essentially free of any of them.
[0066] It is another objective of the present invention to provide
a 4,4'-biphenol polysulfone composition with an outstanding melt
stability at high temperature.
[0067] With this end in view, the present invention concerns a
4,4'-biphenol polysulfone composition containing at least 60% by
weight, based on the total weight of the 4,4'-biphenol polysulfone
composition, of at least one B.sup.o1 PSU, said composition having
a melt viscosity ratio at 410.degree. C. and at a shear rate of 50
s-1 (VR.sub.40), as determined in the examples of the present
application, of below 1.20.
[0068] This composition contains advantageously the same
ingredients, in the same proportions, at any degree of preference,
as the previously described composition, which contained B.sup.o1
PSU, phosphomis-containing compound and B.sup.o1 A PSU.
[0069] It is still another objective of the present invention to
provide a process which is especially well-suited to prepare a
4,4'-biphenol polysulfone composition addressing the problems
raised by the prior art B.sup.o1 PSU compositions as above
detailed.
[0070] With this end in view, the present invention concerns a
process to prepare a 4,4'-biphenol polysulfone composition
comprising: [0071] providing (A) as main ingredient of the
4,4'-biphenol polysulfone composition, at least one polysulfone
comprising more than 50 mol. % of recurring units formed by
reacting 4,4'-biphenol with at least one sulfone monomer SM.sub.1
(B.sup.o1 PSU), [0072] providing (B) more than 0.01% by weight,
based on the total weight of the 4,4'-biphenol polysulfone
composition, of at least one phosphorus-containing compound chosen
from organic phosphites and organic phosphonites, [0073] providing
(C) at least one polysulfone comprising more than 50 mol. % of
recurring units formed by reacting bisphenol A with at least one
sulfone monomer SM.sub.2 (B.sup.o1 A PSU), and [0074] mixing (A),
(B) and (C) at the molten state.
[0075] The 4,4'-biphenol polysulfone composition prepared by the
process according to the present invention complies advantageously
with all the characteristics of the compositions according to the
present invention, as above detailed.
[0076] This implies notably that, in the process according to the
present invention, the amount of the phosphorus-containing compound
is preferably above 0.05%, more preferably above 0.09% and still
more preferably above 0.12% by weight, based on the total weight of
the composition.
[0077] Finally, it is another objective of the present invention to
provide an article made from a B.sup.o1 PSU composition which
solves the problems raised by the prior art articles made from
B.sup.o1 PSU compositions, while maintaining all their beneficial
properties.
[0078] With this last end in view, the present invention concerns
an article made from the above detailed 4,4'-biphenol polysulfone
compositions, or prepared by the above described process to prepare
a 4,4'-biphenol polysulfone composition.
[0079] The article according to the present invention can be
semi-finished or finished. It can be a whole article as such or
just an element of a more complex article.
[0080] The article according to the present invention can be
notably (i) a medical or a dental device component such as a steam
sterilizable medical tray container or a steam sterilizable
surgical handle, (ii) a steam sterilizable lab animal cage (or one
of the related ancillary caging components such as a water bottle),
(iii) a food service component such as an institutional food
serving tray, (iv) an acid or alkali solution container such as a
battery case, (v) a component for plumbing or for hot water
delivery system such as a fitting or a manifold, (vi) a plumbing
fitting for use in food processing, (vii) an aircraft interior
component, (viii) an electrical and/or electronic component such as
a connector, a circuit board, a switch, a relay, a housing or a
magnet wire insulation coating, (ix) an opto-electronic device
component such as a lens, a prism or a wave-guide, (x) a fibre
optic connector, (xi) an impact resistant safety device such as a
helmet, a hard hat or a bump cap, (xii) a semi-finished or finished
extruded shape like a plaque, a sheet, a film, a filament, a
profile or a tubing.
[0081] The article according to the present invention is preferably
chosen from medical and dental device components.
[0082] The article according to the present invention can be
manufactured by any technique which is known by the skilled person.
Non limitative examples of such techniques are injection moulding,
thermoforming, blow moulding, extrusion, as well as any combination
thereof. It is preferably manufactured by an injection moulding
process.
[0083] The composition according to the present invention exhibits
usually an outstanding melt stability at high temperature, i.e. at
such high temperatures, the viscosity of the melt composition
remains almost constant over time, which makes it easy to
manufacture articles based on said composition.
[0084] It has been observed that, in the composition according to
the present invention, not only the phosphorous-containing compound
but also surprisingly the B.sup.o1 A PSU act as melt stabilisers of
the B.sup.o1 PSU (i.e. both contribute to minimise or prevent
viscosity rise at high temperature). Furthermore, in a quite
unexpected way for the skilled person, said B.sup.o1 A PSU and said
phosphorous-containing compound, act in a synergetic way, resulting
in a composition having an outstanding melt stability stability;
this synergetic effect is highlighted when the
phosphorus-containing compound is present in an amount of above
0.05% by weight, based on the total weight of the composition.
[0085] In addition to achieving outstanding melt stability, the
composition according to the present invention retains usually the
key mechanical properties of the B.sup.o1 PSU; furthermore, it is
in general substantially transparent, which increases its
versatility and commercial utility for various uses.
[0086] It is usually observed that, when processing a composition
according to the present invention, no char layer builds on the
walls of tooling that is being used for fabrication (e.g., in the
die in case of an extrusion process or the injection nozzle in the
case of an injection moulding process) or, when such char layer
builds, its formation takes a huge amount of time. Then, no more or
only very spaced-out shut downs and clean up of the installations
are required to remove the char layer. Thereby, the productivity is
increased and the lost production minimised.
[0087] The article according to the present invention is usually
free (or essentially free) of black specks (since no or very few
char forms), and has consequently superior performance or
aesthetics or both.
EXAMPLE 1 (ACCORDING TO THE INVENTION) AND COMPARATIVE EXAMPLES 1
TO 3
[0088] One composition according to the invention (composition E1)
and three compositions to the contrary (compositions CE1, CE2 and
CE3) were prepared. They consisted of the ingredients listed in
Table 1. TABLE-US-00001 TABLE 1 CE1 CE2 CE3 E1 Composition
Identifier (a) B.sup.o1 PSU Radel .RTM. R-5600 NT 100 100 90 90 (b)
Phosphorus-containing -- 0.10 -- -- compound Sandostab .RTM. PEPQ
(b') Phosphorus-containing -- -- -- 0.15 compound Irgafos .RTM. 168
(c) B.sup.o1 A PSU UDEL .RTM. -- -- 10.00 9.85 PXM-98084 Melt
viscosity Melt viscosity at t.sub.o + 10 min 283 287 261 225
[410.degree. C./50 sec.sup.-1] (Pa s) Melt viscosity stability 1.59
1.24 1.30 1.12 VR.sub.40 [410.degree. C./50 sec.sup.-1] (-)
Mechanical Properties Tensile strength (MPa) 76.3 76.6 76.5 77.0
Tensile modulus (MPa) 2482 2544 2454 2454 Tensile yield elongation
(%) 7.9 7.8 7.8 7.6 Tensile elongation at break (%) 103 19 69
83
[0089] Preparation of the compositions. All of them were prepared
by melt compounding in a 25 mm Berstorff co-rotating partially
intermeshing twin-screw extruder.
[0090] Except for CE1, 10 kg mixes were prepared by tumbling the
phosphorus-containing compound (in powder form) and/or the B.sup.o1
A PSU (in the form of pellets), with the B.sup.o1 PSU (also in the
form of pellets), in sealed 5-gallon plastic buckets for 20
minutes. The B.sup.o1 PSU grade itself (CE1) or the mixes (E1, CE2
and CE3) were then fed to the throat of the extruder which was run
at 220 rpm, and a throughput rate of 11.5 kg/h. The Berstorff
machine used consisted of 7 heated barrel sections in addition to
the unheated feed throat section. The first heated barrel section
was vented to the atmosphere while the sixth heated barrel section
was vacuum vented with vacuum levels of 500-650 mm Hg. The heated
barrel section temperature settings were:
315/320/350/345/345/340/345.degree. C. for heated barrel sections 1
through 7, respectively. The die used was a double-hole die and was
set at 345.degree. C. The melt temperature as measured on polymer
extrudate was in the range 390-395.degree. C. The strands exiting
the extruder were cooled in a water bath and were cut into pellets
using a conventional strand cutting pelletizer.
[0091] Determination of the VR.sub.40 ratio (which quantifies the
melt stability of the composition at high temperature). The
extrusion compounded pellets to be tested for stability were dried
under full vacuum (pressure below 71.12 mm Hg) for at least 3 hours
at 150.degree. C. A Kayeness Galaxy V capillary rheometer having a
bore diameter of 9.55 mm and equipped with a 20.32 mm
long.times.1.02 mm diameter die was used. The entrance angle of the
die was 120 degrees. The rheometer barrel was equilibrated at
410.degree. C., then filled with pellets. The pellets were allowed
to melt for 5 minutes, at which time a timer was started (this time
is referred hereafter as t.sub.o). A viscosity reading at a shear
rate of 50 s.sup.-1 was taken from the rheometer at t.sub.o+10 min.
At t.sub.o+40 min, another reading is taken at the same shear rate.
The viscosities at t.sub.o+10 min and at t.sub.o+40 min were both
recorded and the ratio of the viscosity at t.sub.o+40 min to the
viscosity t.sub.o+10 min was calculated; this ratio is the
so-called VR.sub.40. In an ideal composition, VR.sub.40 should be
equal to one.
[0092] Determination of mechanical properties. The extrusion
compounded pellets were dried overnight for 16 hours in a
desiccated air oven at a temperature of 149.degree. C. before they
were injection moulded into 0.125 in-thick ASTM tensile bars and
Izod impact bars. Injection moulding was performed on a 120-Ton
Battenfeld reciprocating screw injection moulding machine using
barrel temperature settings of 350, 350 and 355.degree. C. for the
rear, mid and front barrel sections, respectively. The nozzle
temperature was set at 360.degree. C. The melt temperature was
390.degree. C. and the mould temperature was 148.degree. C. An
injection pressure of 75 bar was used. Screw speed for resin
plastication was set at 250 rpm and the moulding cycle time was 35
seconds.
[0093] Tensile strength, tensile modulus, tensile yield elongation
and tensile elongation at break were measured according to ASTM
method D638.
[0094] Results on melt viscosity and mechanical properties. E1
achieved an outstanding melt viscosity stability ratio VR.sub.40 at
410.degree. C. of 1.12, approaching the ideal viscosity ratio of
1.00. Thereby, it achieved a roughly four fold improvement in melt
stability over CE1, more than a two fold improvement in melt
stability over CE3, and not less than a two fold improvement in
melt stability over CE2. In addition, E1 achieved a high level of
mechanical properties, very similar to that of compositions CE1, CE
2 and CE3.
[0095] Example 1' (according to the invention) and comparative
examples 1' to 3'--Assessment of the char formation. Compositions
E1', CE1', CE2' and CE3', having exactly the same chemical nature
as respectively compositions E1, CE1, CE2 and CE3, were prepared at
a larger scale (semi-pilot scale) using a W&P ZSK-40 twin screw
extruder, with 12 barrels or temperature zones (B1 to B12). The set
point temperatures were respectively: 200.degree. C. in B1 (feed
zone), 330.degree. C. from B2 to B4, 340.degree. C. from B5 to B6
and 345.degree. C. from B7 to B12. The first heated barrel section
was vented to the atmosphere while the other heated barrel section
were vacuum vented. The screw speed was 300 rpm. All the
compositions were processed in exactly the same conditions.
[0096] When comparative example 1' was run in the above extrusion
process with melt temperatures approaching 420.degree. C. charring,
and pluggage of die tooling with black specks plugging the
extrusion nozzle orifice after relatively short run durations were
observed. Essentially the same happened when running comparative
examples 2' and 3', but after a slightly longer run and with a
slightly less intensity. Conversely, when example 1 was run in the
same process in the same operating conditions, neither pluggage of
die tooling nor black specks plugging the extrusion nozzle orifice
were observed even after a long time.
* * * * *